Regular Expressions (regex) are symbolic notations that are used to identify patterns in text.
Regex is useful for identifying strings, patterns of characters, words of particular interest. After your set of strings are found, you can either print it out, replace it, or perform other manipulative tasks.
Knowing how to write and use regex provide the tools to quickly identify, count and manipulate strings of interest. Furthermore, regex gives you the flexibility as a programmer to apply tasks such as "find and replace" in a matter of milliseconds that would otherwise takes minutes to perform manually.
If you're looking to learn regular expressions for the shell or the Linux command line, head on over to our Command Line Regular Expressions tutorial page.
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